Salvatore “Sammy Bull” Gravano chickened out of testifying at his pre-sentencing hearing yesterday after a mob wannabe ratted him out for hatching murder plots – and planning to form his own mob.

Admitted “ecstasy” manufacturer Philip Pascucci, 36, told the court the former Gambino underboss took him under his wing, and was grooming him to be a mob hit man in Arizona.

Gravano tried to lure him in by telling the star-struck Pascucci to get a brazen vanity plate taken off his car – as revealed in a note the notorious mobster penned on a copy of his tell-all biography “Underboss.”

“Phil, Glad you’ve moved ‘WISEGUY’ off your license plate and into your heart; Your next Boss and Pal, Sammy.”

“I would be in this family right off the bat, so there would be no initiation for me to come in,” Pascucci told Assistant U.S. Attorney Noah Perlman.

Defense lawyer Lynne Stewart said Gravano – whose cooperation nailed “Teflon Don” John Gotti – wanted to take the stand at the two-day hearing that wrapped up yesterday.

But he couldn’t in light of testimony that implicated him in numerous new conspiracies.

“I think he understands that once the name Gravano is invoked, things really are skewed out of proportion,” Stewart said.

Under normal guidelines, Gravano would face 12 to 15 years in prison after pleading guilty to ecstasy distribution charges last year.

Perlman and Assistant U.S. Attorney Linda Lacewell, however, want Brooklyn federal Judge Allyne Ross to give Gravano the max – 20 years – for throwing away a sweetheart deal that allowed him to serve just five years for 19 murders.

No sentencing date has been set.

On the stand, Pascucci rattled off several murder plots Gravano allegedly had in the works.

There was the 1998 plot against New York lawyer Ronald Kuby, who slapped Gravano with a $50 million suit on behalf of his murder victims’ families after “Underboss” was published.

Other murder plots included the girlfriend of Gravano’s son, Gerard, who reportedly spat in Bull’s face, a Texas drug thug and partner to Pascucci, and the rat who told the feds where Gravano liked to dine every weekend.

Gravano even agreed to do two hits for an Arizona thug if the thug would kill Gravano’s brother-in-law in New York.